The invention relates to a lancet which on an upper face comprises at least one upwardly open channel for receiving a sample.
Upon lancing the body of a patient, the channel fills with body fluid, generally blood or interstitial liquid, due to capillary forces. Lancets comprising such capillary channels thus allow easy withdrawal of small samples of body fluids and thereby facilitate measurements of the concentrations of medically significant analytes, for example glucose or lactate.
So as to measure the analyte concentration, the sample must be transferred to a test field which contains detection reagents. Such a test zone can be provided directly on the lancet, as is known from WO 2005/084530 A2. The sample is then transported in the channel to the test zone by way of capillary forces.
An alternative to lancets comprising integrated test fields are systems which include lancets and separate test elements. In such systems, a sample is transferred from the channel to the test element by pressing the lancet against the test element, which is to say the upper face of the lancet forms a contact surface for placing a test element thereon. The sample contained in the channel can then be taken up by the test element. Such a system is known from EP 2263526 A1, for example. Test elements and lancets can be arranged on a carrier tape or they can be present as loose, individual parts of the system.
Providing test fields on lancets is complex for manufacturing reasons. Systems composed of lancets and separate test elements thus have the advantage of being comparatively inexpensive to manufacture, however the transfer of sample fluid from a lancet to a test element is problematic.